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160 Cards in this Set
- Front
- Back
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Sellar mass
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Pituitary macroadenoma
Craniopharyngioma Rathe’s cleft cyst |
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Rathke’s cleft cyst
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arises from failure of obliteration of the lumen of Rathke’s pouch, which develops as a rostral outpouching of the primitive oral cavity; Rathke’s pouch has an anterior and posterior portion and a central embryonic cleft; - anterior wall becomes the anterior lobe of the pituitary gland and the pars tuberalis; the posterior wall becomes the pars intermedia; residual lumen of the pouch is reduced to a narrow Rathke’s cleft which generally regresses. It’s persistence and enlargement is said to be the cause of the symptomatic Rathke’s cleft cyst.
· MRI: cystic intrasellar mass with extension into the suprasellar region and usually (two-thirds) T1-bright signal intensity and variable T2-intensity. · Ddx: cystic craniopharyngiomas or cystic pituitary adenomas; enhancement of the wall in a cystic neoplasm may help differentiate neoplasms from non-neoplastic cysts. (Craniopharyngioma will enhance.) · small and asymptomatic; may present with HA(most common), visual disturbance, hypopituitarism or diabetes insipidus. · Tx: cyst aspiration and partial removal |
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Suprasellar mass
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SATCHMOE
Sellar lesion- adenoma Aneurysm, Arachnoid cyst Teratoma- germinoma, dermoid, epidermoid Cranipharyngioma Hypothalamic glioma, hamartoma of tuber cinerium Meningioma Mets Optic glioma- NF EG Ddx: infundibular thickening adult – sarcoid, TB, meningitis, mets, glioma, lymphoma, germinoma, lymphocytic hypophysitis (preg women), choristoma: peds - EG, suprasellar germinoma (Diabetes inspidus) (ectopic pituitary, no stalk, ped) (Rathke’s cleft cyst- sellar, variable signal) |
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Pituitary apoplexy
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massive hem into pit adeoma (bromocriptine), necrosis, or infarct
Sheehan- post partum infarct of ant pit Hetero signal, hi T1 |
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Intraventricular tumors- adults
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glioma- astro, incl giant cell c TS- calc, subependymoma, oligo,
meningioma- trigone, follows GM signal- rel low T2 mets cysticercosis- V3 central neurocytoma- septum (arise/abutt) colloid cyst – V3 |
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Lesion near foramen monro
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colloid cyst- variable signal, typical hi T1/low T2
giant cell astrocytoma- TS cysticercosis |
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Intraventricular tumors- kids
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ependymoma- V4 (supratent- NOT intravent)
choroid plexus papilloma- trigone>V3 pnet teratoma astrocytoma eg of stalk (xanthogranuloma- lat, older, usu bilat, large, calc, fat, cyst) |
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Third ventricle (V3) mass
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Colloid cyst
Glioma (giant cell astrocytoma) Meningioma Choroid plexus papilloma-frondy Aneurysm Pineal lesions Craniopharyngioma- adults (Cystic- arahnoid cyst, ependymal cyst, cysticerc) |
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Choroid plexus papilloma
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most <2y, M>>F
trigone (kids)> V4 (adults) large, smooth lobulated, calcs, engilf glomus of c.p., fronds vent dil- CSF overproduction intense homo enhancement |
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Post fossa mass- peds
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Medulloblastoma: (M>f, vermis c extension to 4th vent c edema- displ and efface v4, necrosis or cystic change in up to 50%, ca 20%, heme rare, CT: solid, HYPER, MR: hypo t1, variable t2, intense enhancement
csf seeding common & systemic (5%) mets Astrocytoma (Juvenile pilocytic astrocytoma): (Inc freq in NF, can, occur optic & cerebrum, most @ vermis, can extend to cerebellar hem cystic c mural nodule or solid, CT: iso or hypo, MR: iso/hypo t1, hyper t2, nodule intensely enhance, vs hemangioblastoma (adult)) Ependymoma: (usu 4th vent, can be supratent (parench), 30% - 50% calcify, **extension thru foramen of Luschka into cp °, thru Magendie to cisterna magna & foramen magnum, high recurrence, ct: hetero iso calcs and hem much more common than med and expand rather than displ) Brainstem glioma: (peak: 3-10, high recur, poor px, usu anaplastic, GBM, RT, *exophytic growth to adjacent cisterns, *pontine enlargement (pons extends beyond basilar a), *alteration of 4th vent contour Choroid plexus papilloma |
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Pineal region masses
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Germ cell tumors (60%)
germinoma: m>>f- dense on CT, calcs teratoma- fat embryonal carcinoma endodermal sinus tumor choriocarcinoma- bleed Pineal parenchymal (14%) Pineocytoma Pineoblastoma - PNET highly malig (also c trilateral retinoblastoma) other pineal cyst glioma meningioma (tentorial) vein of Galen aneurysm arachnoid cyst lipoma |
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Supratentorial cystic mass c enhancing nodule
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Pleomorphic xanthoastrocytoma
Ganglioglioma/gangliocytoma- young adults Desmoplastic infantile ganglioglioma (DIG)- infant, most F and P, sz, enlarging head, nodule superficial Large tumors, superficial, no sig edema, seizures |
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DNET (dysembryoplastic neuroepithelial tumor)
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gr 1, always presents c seizures
Cortical, often TL no edema, calc, enhance, well def multicystic megagyric- can remodel bone- LA, hi T2, nl wm thru lesion, like thick ctx cortical dysplasia developmental lesion? |
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Extra-axial lesion (neuro - brain)
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Mets to bone
Meningioma- encase/narrow cav ICA typical Hemangiopericytoma Granulocytic sarcoma/chloroma- AML Arachoid cyst Epidermoid Intracranial plasmacytoma- mimics meningioma Bony lesion Empyema |
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CNS lymphoma
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AIDS
B-cell nNHLl multifocal, well-demarcated enhancing (focal) lesions scattered in wm, periventricular most supratent, can be central-thal ca/hem rare spread via cc hypo t2, hyper ct difficult to differentiate from toxo (usu @ g/w jxn & bg) systemic dz involves leptomeninges |
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Ring enhancing lesions
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MAGIC DR
Mets- SCC (cystic) Abscess- infection, including TB*, toxo Glioma Infarct, resolving Contusion Demyelinating- tumefactive MS, ADEM, lyme Radiation necrosis, resolving hematoma |
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Cavernous sinus lesion
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(CN 3,4,5,6)
schwanoma menigioma- encases/narows ica- typical pituitary adenoma lymphoma aneurysm chordoma chondrosarcoma infection carotid-cavernous fistula |
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PICA infarct
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dorsolateral medullary infarct – Wallenberg syndrome
ipsilateral facial pain/numbess contralateral dec pain/temp nystagmus/ataxia/diplopia |
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Venous infarction
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due to SSST with propogation of clot into cortical veins
parasagittal edema – cortical/subcortical WM |
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MR blood (timing and signal in stroke)
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acute (7-72 hrs) - deoxy (intracell, para) - I , D
early subacute (4-7d)- met (ferric)- (intra) - B , D late subacute (1-4w) - met (extra)- B, B chronic (mos) - hemosiderin- D, D hyperacute- oxyhb (diamagnetic, does not affect mr signal) - t1- iso, t2- bright gradient echo- deoxy & hemosiderin- dark (and calc) |
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Intracranial hemorrhage/hematoma Ddx:
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Aneurysm/AVM
Angiopathy (amyloid, vasculitis) Tumor (primary – glioma); mets; melanoma, renal cell, chorioca, thyroid, common – lung, breast ; HIV – toxo, lymphoma Hemorrhagic infarct Hypertensive hemorrhage – bg, pons, cerebellum; can be secondary to COCAINE Coagulopathy Trauma |
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Ddx for abnormal FLAIR signal in SAH:
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Blood
Carcinomatosis Meningitis Infarct anesthesia |
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Cortical abnormal signal
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Infarct – can be metabolic – i.e. MELAS
Glioma Cerebritis/encephalitis (demyelinating c WM) |
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Laminar necrosis
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Ischemic changes affecting deep sensitive layers of ctx
Acute- linear hi T1, enhance, WM edema T2 Chronic- thin hpointense ctx?, big csf space Global anoxia |
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Cortical infarct- CT and MR enhancement timing
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Hyperacute <12 h
Dense MCA, loss ribbon Edema Acute- early (12-24h) *Cortical arterial vessel enhancement- slow flow via collaterals Subtle cortical low T1/hi T2 Loss G-W Acute- late (1-7d) Gyral enhancement- CT *Intravscular enhancement- MR- vessels supplying infarct p 1-3 d *Meningeal enhacement- mr *Subacute (7-30d) Less mass effect Gyral blush and ring enhancement- Ct *Gyriform parenchymal enhancement- mr Chronic (>30d) Atrophy, encephalomalacia, gliosis Wallerian degeneration of corticospinal tracts No enhancement |
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Dissection
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Trauma
Fibrous dysplasia Marfan’s/E-D Cystic medial necrosis |
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Moyamoya
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Occlusion of the supraclinoid ICA and proximal ACA, MCA, PCA of unknown etiology; prominent collaterals in BG from lenticulostriates and thalamoperfororators; dx of exclusion
o Ddx: sickle cell, RT, Meningioma, basal meningitis, NF1 |
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Sickle Cell Disease in Neuro
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infarction related to stasis and ischemia in the vasa vasorum, leading to intimal and medial hyperplasia with eventual significant narrowing or occlusion of the ICA or prox ACA and MCA. This can look like moyamoya with prominent collateral circulation
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AVM
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Enlarged feeding artery – have aneurysm along artery – due to high flow
Core /nidus – aneurysm here prone to rupture Enlarged draining vein Encephalomalacia may be present due to “steal” phenomenon CT: vessels appear iso-hyperdense due to blood; calcification may be seen MRI: serpentine flow voids Tx: depends on size, location Embo, Sx, radiation Embo often staged; as AVM is occluded, avoid increased blood flow to ischemic brain which can become edematous and hemorrhage 15% are dural; 50% in PF – dural arterial flow; drains into sigmoid/transverse sinuses; etiology – venous thrombosis and development of collaterals with venous hypertension; if blood drains into cortical veins – at risk for venous infarction and/or intracranial hemorrhage (intraparechymal/SAH) |
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Abnormal signal deep gray
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Degenerative
Metabolic Toxic |
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Bilateral thalamic lesions (high T2)
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Venous or arterial (basilar tip) infarct
Encephalitis Glioma Metabolic – anoxia, Wernike, Wilson, osmotic myelinolysis |
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BG Hi T1
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Hypoxic-ischemic encephalopathy - neonates
liver failure hyperpara & hypopara & pseudohypo hyperalimentation porto systemic shunt depo of paramag ions- low on T2, globus pallidus- Krabbe’s dz |
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BG hi T2, symmetric
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anoxia- CO, smoke inhalation, near drowning
Leigh’s dz- sporadic, lactic acidosis Creutzfeldt-Jakob dz- caudate head and putamen Hallervorden-Spatz dz- destruction of globus pallidus and substantia nigra- initial low T2 of globus pallidus then hi T2 |
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Low T2 globus pallidus and thalami
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never NL (iron depo)- nonspecific- neurodegenerative
Demyelinating (MS) Leukodystrophy- Krabbe’s Brain anoxia/infarct Wilson’s Hallervorden-Spatz Metabolic Sig head trauma |
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BG Calcs
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in utero HIV
hyperpara & hypopara tb, cysticercosis CO- globus pallidus Lead Idio- senecent- g.p. Fahr dz- familial cerebrovascular ferrocalcinosis- extensive bilat bg calc & dentate nuclei & wm- deep & subcortical |
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Leptomeningeal enhancement
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Mets- primary CNS and non- PNET, med, lung, breast, lymphoma, melanoma
Meningitis- bact, TB, fungal, chemical –rupture dermoid Sarcoid- also parenchymal and mimic meningioma SAH, old Post surgical |
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Leptomeningeal carcinomatosis
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mimic meningitis
cranial nerve palsies, hcp (involve basal cisterns) 1° cns adeno (breast, lung) leukemia/lymphoma |
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Dural enhencement
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Mets- prostate, breast, neuroblastoma (kid)
Lymphoma/leukemia Child - neuroblastoma Meningioma Granulomatous- TB, sarcoid, Wegener’s Spont iC hypotension – post LP Post cranial sx Chronic subdural hematoma Idiopathic hypertrophic pachymeningitis |
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Enhancing ventricular margins
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Subependymal mets- lung, breast, melanoma
Sub/ependymal seeding of CNS primary- med, glioma, epen Lymphoma Inflammatory ventriculitis |
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WM abnormality
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MS- Marburg (acute, younger, fever, rapid,extensive), Devic (optic neuritis and cord), tumefactive
ADEM- Hursts (acute hemorrhagic leukoencephalitis), viral, vax. monophasic PML SSPE? Vasculitis Migraine Lyme Leukodystrophy CADASIL- Cerebral Aut Dom Arteriopathy c Subcortical Infarcts & Leukoencephalopathy MVID DAI Diffuse necrotizing leukoencephalopathy- intrathecal MTX, RT Transependymal CSF flow |
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Epidural and subdural abscess/empyema
(head) |
Extension from sinusitis, frontal
Craniotomy Meningitis Epidural- thru midline but not sutures Cx: cerebritis, abscess, venous sinus thrombosis |
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Basal meningitis (granulomatous)
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TB
Sarcoidosis – likes cranial nerves – optic nerve Fungal- crypto, candida, cocci, mucor, blasto, nocardia, actino Cerebritis, abscess, HCP |
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Infections
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HSV- med TEMPORAL, insula, limbic, usu uni, edema, hem, enhance, can be bi
HIV- atrophy, PV wm dz, often c CMV Cysticercosis parenchymal- sz, neuro def intraventricular- obs hcp subarachnoid- comm hcp IM cord-rare Cryptococcosis- gelatinous pseudocysts, meningitis Abscess- thin wall cventral- rupture into vent, ventriculitis (ependymitis) |
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Limbic encephalitis
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Paraneoplastic- small cell (also cerebellar degen), ovarian, GI, breast, Hodgink, NB
Autoimmune. AMS, memory impaired Medial temporal lobes, hypothal, +/- mild enhance, usu bilat Ddx: herpes, CO (c globus pallidus involvement) |
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Rhombencephalitis- LISTERIA
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immunocomp, occupational (farm animals)
meningitis or enceph predilection for BRAINSTEM & CEREBELLUM may enhance can cause abscess ddx: tb, syphilis, sarcoid, ms, adem |
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SSPE (subacute sclerosing panencephalitis)
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P measles, p 5 y
Slow, preogressive or rapid PVWM, BG, cerebellum, brainstem No enhancement, later-diffuse cortical atrophy |
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Holoprosencephaly- no septum pellucidum in all
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Alobar- c severe facial anomalies, monoventricle, fused thal
Semilobar- intermediate- aprtial falx/fissure, partial occipital Lobar- mild- unseparate frontal horns, falx may be present Trisomies 13, 18 |
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Hydranencephaly
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Sec to in utero vascular insult- spared post fossa
alobar holoprosencephaly- no septum/fissure bilat open lip schizencephaly- assoc c septo-optic dysplasia, interhem fissure preserved maximal hydrocephalus- thinned but present mantle of cortex |
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NF
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optic gliomas c extension to tracts
cerebral gliomas UBO- brainstem, pons, BG, thal, cerebellum- can enhance, dysmyel? *think of neurocut stuff in kids- nf, ts, s-w |
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NF2
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bilat vestib schwannoma (or ther CN)
meningioma ependymoma |
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Alexander’s dz
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dysmyelinating. M, sporadic, big head, frontal to post
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Dysmyelinating dz
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Alexander’s- M, sporadic, big head, frontal to post
Canavan’s dz- jewish, AR, big head, occipital, extensive peripheral WM involvement* Krabbe’s dz- dense thalami, corona, caudate body (low T2- paramagnetic) Adrenoleukodystrphy- central occipital to periph and anterior, X Metachromatic leukodystrophy- most common hereditary, AR, symmetric pvwm, atrophy Leigh’s dz (subacute necrotizing ecephalopathy)- AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT) |
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Canavan’s dz
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Dysmyelinating dz. jewish, AR, big head, occipital, extensive peripheral WM involvement*
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Krabbe's dz
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Dysmyelinating dz. dense thalami, corona, caudate body (low T2- paramagnetic)
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Adrenoleukodystrophy
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Dysmyelinating dz. central occipital to periph and anterior,5-10 yrs, x linked
symmetric, confluent posterior white matter, atrophy peripheral rim enhancement- active calcs unusual long chain fatty acids adrenal insufficiency |
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Metachromatic leukodystrophy
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Dysmyelinating dz. most common hereditary, AR, symmetric pvwm, atrophy
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Leigh's dz (subacute necrotizing encephalopathy)
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Dysmyelinating dz. AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT)
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Agnesis of corpus callosum
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assoc c: (colpocephaly, bat wing, high riding V3, absent septum pellucidum)
HCP Dandy-walker Chiari II Midline lipoma- interhem, suprasellar and quad cisterns, not true neoplasm Holoprosencephaly Porencephaly Encephalocele Can be isolated, Probst bundles, absent cingulate gyrus Ant CC usu present c dysgenesis |
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Absence Of Septum Pellucidum
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Holoprosencephaly
Septo-optic dysplasia- assoc c schizencephaly, absent olfactory bulbs Callosal agenesis Schizencephaly Severe chronic hydrocephalus Destructive porencephaly |
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Heterotopia
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Migrational anomaly, sz
Subependymal, ant and post horns- iso to GM, no enhance Band (laminar)- subcortical WM Ddx: subependymal tumor spread, heme, vascular malform, TS, IV meningioma, NF |
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Rhombencephalosynapsis
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fused cerebellum, dent nuclei, sup cerer peduncle, thal
absent vermis, v4 pointed post- keyhole absent septum pellucidum |
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Gray matter heterotopia
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Subependymal
Deep white matter Band heterotopia- often symmetric |
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Sturge-Weber
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facial vascular nevus in the territory of the ophthalmic division of the trigeminal nerve, seizures, dementia, hemiplegia, hemianopsia, and congenital glaucoma or buphthalmos
sporadic characteristic leptomeningeal venous angioma (subarachnoid space) and facial nevus are most commonly unilateral, but may be bilateral Intraparenchymal calcification, parenchymal volume loss, engorgement of deep veins, and leptomeningeal and choroid plexus angiomata*- calcify and hi T2 Cortical calcs: pericapillary distribution in the fourth layer of the atrophied cerebral cortex- may not see on MR- gre/T2 only Mr: thickened ctx and dec convolutions- Atrophy Assoc c ddm synd |
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Dyke davidoff mason
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Ipsilateral hypertrophy of cranium secondary to cerebral hemiatrophy (compensatory thickening of inner table)
Enlarged orbits, sinuses, mastoids, thick ctx Sec to vasc insult Also c Sturge-Weber |
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J-shaped sella
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CONMAN
Chronic hydrocephalus Optic glioma, OI neurofibromatosis Mucopolysaccharidosis Achonondroplasia Normal variant |
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Basilar invagination
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Chamberlain and McGregor’s line- dens>5 mm above- superior migration of dens thru foramen magnum
Compresses cord/brainstem "PF ROACH" Paget disease Fibrous dysplasia Rickets Osteogenesis imperfecta, Osteomalacia Achondroplasia Cleidocranial dysplasia Hyperparathyroidism, Hurler syndrome |
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Wernike’s encephalopathy
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Bilat symmetric thalamic hi T2
Alcoholics and vomiting preg Reversible c thiamine Ddx: osmotic myelinolysis |
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Cerebellar atrophy
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Generalized- c cerebral atrophy
Olivopontocerebellar degeneration- Friedreich ataxia Ataxia-telangiectasia – AR, sinopulm infections, ICH, lymphoma/leukemia EtOH- midline (vermis) Dilantin Paraneoplastic (usu small cell) Radiation Focal- trauma, infarct |
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Posterior reversible encephalopathy syndrome (PRES)
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@ g-w jxn, ext capsule, bg, cortical & subcortical wm (OCCIPITAL)- neg DWI
sz, visual disturbance, obtundation, resolves w/in days HTN-acute elev of BP as little as 10 mmHg preeclampsia/eclampsia - htn, proteinuria, +sz/coma Cyclosporine toxicity, OKT3- immunosup Cocaine, heroin Chemorx: MTX, cisplatin CRF? TTP, HUS? SLE(rare) |
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Diffuse cerebral atrophy
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Degenerative - Alzheimer’s, Pick, J-C dz- caudate head/putamen and cortical gyriform hi T2, no WM/gad
MS, encephalitis Trauma Radiation Drugs- dilantin, steroids, MTX, pot, chemo, EtOH HIV encephalopathy Infarcts Renal failure Age Anorexia Dyke-davidoff-mason- unilat |
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Gyral enhacement
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Meningeal carcinomatosis- breast, lung, melanoma, lymphoma
Primary cns tumor c seeding- medulloblastoma, pineoblastoma, ependymoma Meningitis- any Cerebritis- focal/encephalitis- diffuse, viral SAH Subacute infarct |
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Ventricular margin enhancement
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Subependymal met extension- small cell, breast, melanoma
Subependymal seeding of CNS primary- glioma, ependymoma, medulloblastoma, germinoma Lymphoma Ventriculitis- rupture or from basal cisterns |
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Ventriculitis
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Trauma
Absecess rupture Bacteremia Surgical (shunt) Meningitis Hiv- CMV, lymphoma |
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Diffuse axonal injury (DAI)
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Locations
1. Lobar WM- F/T 2. CC- posterior 3. Brain stem- dorsolateral pons/mid Shearing, petch hem later Severe neuro deficit |
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Persistent trigeminal artery
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up to 1/2%
hypoglossal & otic assoc c avm & aneurysms can course thru sella** usu precavernous, can be intracavernous prox basilar & distal vert & pcom can be hypoplastic assoc c tic doloureux & vb insuff |
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Spontaneous intracranial hypotension
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Postural HA
Iatrogenic (LP, surgery), spontaneous (rupture of Tarlov cyst), trauma, thoracic diverticula Chronic, intermittent CSF leak Low-lying tonsils, elongated V4, bilat dubdural effusion, dural enhancement |
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CNS vasculitis
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infect- tb, syphilis
non-infect Primary angiitis PAN Sarcoid wegener's coll-vasc- SLE, RA antiphospholipid ab- ischemia drugs- amph, x, coke primary (isolated) angiitis of the CNS (PACNS) no systemic vasculitis *systemic c CNS involvement Churg-Strauss PAN** (most cmmn to affect CNS) Microscopic polyangiitis (lung and kids) Wegener's Behcet's dz- nonspec, BG, brainstem, WM giant cell arteritis SLE usu stroke antiphospholipid ra, scleroderma, sjogren's |
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Lhermitte-duclos
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posterior fossa dysplasia, mimicking a space-occupying lesion; aka - dysplastic gangliocytoma of the cerebellum and is considered a complex hamartoma; may occupy an entire cerebellar hemisphere; macroscopically the cerebellar folia appear hyperplastic. CT may be misleading since it shows a poorly delineated iso- or hypointense posterior fossa lesion without enhancement but with deformity of the fourth ventricle associated sometimes to hydrocephalus, that may mimic a posterior fossa neoplasm. MR shows a characteristic T2 pattern of laminated increased signal – like “tiger stripes”
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MELAS
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(mitochondrial encephalopathy, lactic acidosis and stroke)- infarcts not confined by vascular territory, spares WM, hits cortex where there is high metabolic activity, familial
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MERRF
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myoclonus, epilepsy, ragged red fibers)- adults
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Sellar mass
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Pituitary macroadenoma
Craniopharyngioma Rathe’s cleft cyst |
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Rathke’s cleft cyst
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arises from failure of obliteration of the lumen of Rathke’s pouch, which develops as a rostral outpouching of the primitive oral cavity; Rathke’s pouch has an anterior and posterior portion and a central embryonic cleft; - anterior wall becomes the anterior lobe of the pituitary gland and the pars tuberalis; the posterior wall becomes the pars intermedia; residual lumen of the pouch is reduced to a narrow Rathke’s cleft which generally regresses. It’s persistence and enlargement is said to be the cause of the symptomatic Rathke’s cleft cyst.
· MRI: cystic intrasellar mass with extension into the suprasellar region and usually (two-thirds) T1-bright signal intensity and variable T2-intensity. · Ddx: cystic craniopharyngiomas or cystic pituitary adenomas; enhancement of the wall in a cystic neoplasm may help differentiate neoplasms from non-neoplastic cysts. (Craniopharyngioma will enhance.) · small and asymptomatic; may present with HA(most common), visual disturbance, hypopituitarism or diabetes insipidus. · Tx: cyst aspiration and partial removal |
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Suprasellar mass
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SATCHMOE
Sellar lesion- adenoma Aneurysm, Arachnoid cyst Teratoma- germinoma, dermoid, epidermoid Cranipharyngioma Hypothalamic glioma, hamartoma of tuber cinerium Meningioma Mets Optic glioma- NF EG Ddx: infundibular thickening adult – sarcoid, TB, meningitis, mets, glioma, lymphoma, germinoma, lymphocytic hypophysitis (preg women), choristoma: peds - EG, suprasellar germinoma (Diabetes inspidus) (ectopic pituitary, no stalk, ped) (Rathke’s cleft cyst- sellar, variable signal) |
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Pituitary apoplexy
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massive hem into pit adeoma (bromocriptine), necrosis, or infarct
Sheehan- post partum infarct of ant pit Hetero signal, hi T1 |
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Intraventricular tumors- adults
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glioma- astro, incl giant cell c TS- calc, subependymoma, oligo,
meningioma- trigone, follows GM signal- rel low T2 mets cysticercosis- V3 central neurocytoma- septum (arise/abutt) colloid cyst – V3 |
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Lesion near foramen monro
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colloid cyst- variable signal, typical hi T1/low T2
giant cell astrocytoma- TS cysticercosis |
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Intraventricular tumors- kids
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ependymoma- V4 (supratent- NOT intravent)
choroid plexus papilloma- trigone>V3 pnet teratoma astrocytoma eg of stalk (xanthogranuloma- lat, older, usu bilat, large, calc, fat, cyst) |
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Third ventricle (V3) mass
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Colloid cyst
Glioma (giant cell astrocytoma) Meningioma Choroid plexus papilloma-frondy Aneurysm Pineal lesions Craniopharyngioma- adults (Cystic- arahnoid cyst, ependymal cyst, cysticerc) |
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Choroid plexus papilloma
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most <2y, M>>F
trigone (kids)> V4 (adults) large, smooth lobulated, calcs, engilf glomus of c.p., fronds vent dil- CSF overproduction intense homo enhancement |
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Post fossa mass- peds
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Medulloblastoma: (M>f, vermis c extension to 4th vent c edema- displ and efface v4, necrosis or cystic change in up to 50%, ca 20%, heme rare, CT: solid, HYPER, MR: hypo t1, variable t2, intense enhancement
csf seeding common & systemic (5%) mets Astrocytoma (Juvenile pilocytic astrocytoma): (Inc freq in NF, can, occur optic & cerebrum, most @ vermis, can extend to cerebellar hem cystic c mural nodule or solid, CT: iso or hypo, MR: iso/hypo t1, hyper t2, nodule intensely enhance, vs hemangioblastoma (adult)) Ependymoma: (usu 4th vent, can be supratent (parench), 30% - 50% calcify, **extension thru foramen of Luschka into cp °, thru Magendie to cisterna magna & foramen magnum, high recurrence, ct: hetero iso calcs and hem much more common than med and expand rather than displ) Brainstem glioma: (peak: 3-10, high recur, poor px, usu anaplastic, GBM, RT, *exophytic growth to adjacent cisterns, *pontine enlargement (pons extends beyond basilar a), *alteration of 4th vent contour Choroid plexus papilloma |
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Pineal region masses
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Germ cell tumors (60%)
germinoma: m>>f- dense on CT, calcs teratoma- fat embryonal carcinoma endodermal sinus tumor choriocarcinoma- bleed Pineal parenchymal (14%) Pineocytoma Pineoblastoma - PNET highly malig (also c trilateral retinoblastoma) other pineal cyst glioma meningioma (tentorial) vein of Galen aneurysm arachnoid cyst lipoma |
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Supratentorial cystic mass c enhancing nodule
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Pleomorphic xanthoastrocytoma
Ganglioglioma/gangliocytoma- young adults Desmoplastic infantile ganglioglioma (DIG)- infant, most F and P, sz, enlarging head, nodule superficial Large tumors, superficial, no sig edema, seizures |
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DNET (dysembryoplastic neuroepithelial tumor)
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gr 1, always presents c seizures
Cortical, often TL no edema, calc, enhance, well def multicystic megagyric- can remodel bone- LA, hi T2, nl wm thru lesion, like thick ctx cortical dysplasia developmental lesion? |
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Extra-axial lesion (neuro - brain)
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Mets to bone
Meningioma- encase/narrow cav ICA typical Hemangiopericytoma Granulocytic sarcoma/chloroma- AML Arachoid cyst Epidermoid Intracranial plasmacytoma- mimics meningioma Bony lesion Empyema |
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CNS lymphoma
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AIDS
B-cell nNHLl multifocal, well-demarcated enhancing (focal) lesions scattered in wm, periventricular most supratent, can be central-thal ca/hem rare spread via cc hypo t2, hyper ct difficult to differentiate from toxo (usu @ g/w jxn & bg) systemic dz involves leptomeninges |
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Ring enhancing lesions
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MAGIC DR
Mets- SCC (cystic) Abscess- infection, including TB*, toxo Glioma Infarct, resolving Contusion Demyelinating- tumefactive MS, ADEM, lyme Radiation necrosis, resolving hematoma |
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Cavernous sinus lesion
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(CN 3,4,5,6)
schwanoma menigioma- encases/narows ica- typical pituitary adenoma lymphoma aneurysm chordoma chondrosarcoma infection carotid-cavernous fistula |
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PICA infarct
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dorsolateral medullary infarct – Wallenberg syndrome
ipsilateral facial pain/numbess contralateral dec pain/temp nystagmus/ataxia/diplopia |
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Venous infarction
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due to SSST with propogation of clot into cortical veins
parasagittal edema – cortical/subcortical WM |
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MR blood (timing and signal in stroke)
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acute (7-72 hrs) - deoxy (intracell, para) - I , D
early subacute (4-7d)- met (ferric)- (intra) - B , D late subacute (1-4w) - met (extra)- B, B chronic (mos) - hemosiderin- D, D hyperacute- oxyhb (diamagnetic, does not affect mr signal) - t1- iso, t2- bright gradient echo- deoxy & hemosiderin- dark (and calc) |
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Intracranial hemorrhage/hematoma Ddx:
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Aneurysm/AVM
Angiopathy (amyloid, vasculitis) Tumor (primary – glioma); mets; melanoma, renal cell, chorioca, thyroid, common – lung, breast ; HIV – toxo, lymphoma Hemorrhagic infarct Hypertensive hemorrhage – bg, pons, cerebellum; can be secondary to COCAINE Coagulopathy Trauma |
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Ddx for abnormal FLAIR signal in SAH:
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Blood
Carcinomatosis Meningitis Infarct anesthesia |
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Cortical abnormal signal
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Infarct – can be metabolic – i.e. MELAS
Glioma Cerebritis/encephalitis (demyelinating c WM) |
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Laminar necrosis
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Ischemic changes affecting deep sensitive layers of ctx
Acute- linear hi T1, enhance, WM edema T2 Chronic- thin hpointense ctx?, big csf space Global anoxia |
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Cortical infarct- CT and MR enhancement timing
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Hyperacute <12 h
Dense MCA, loss ribbon Edema Acute- early (12-24h) *Cortical arterial vessel enhancement- slow flow via collaterals Subtle cortical low T1/hi T2 Loss G-W Acute- late (1-7d) Gyral enhancement- CT *Intravscular enhancement- MR- vessels supplying infarct p 1-3 d *Meningeal enhacement- mr *Subacute (7-30d) Less mass effect Gyral blush and ring enhancement- Ct *Gyriform parenchymal enhancement- mr Chronic (>30d) Atrophy, encephalomalacia, gliosis Wallerian degeneration of corticospinal tracts No enhancement |
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Dissection
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Trauma
Fibrous dysplasia Marfan’s/E-D Cystic medial necrosis |
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Moyamoya
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Occlusion of the supraclinoid ICA and proximal ACA, MCA, PCA of unknown etiology; prominent collaterals in BG from lenticulostriates and thalamoperfororators; dx of exclusion
o Ddx: sickle cell, RT, Meningioma, basal meningitis, NF1 |
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Sickle Cell Disease in Neuro
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infarction related to stasis and ischemia in the vasa vasorum, leading to intimal and medial hyperplasia with eventual significant narrowing or occlusion of the ICA or prox ACA and MCA. This can look like moyamoya with prominent collateral circulation
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AVM
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Enlarged feeding artery – have aneurysm along artery – due to high flow
Core /nidus – aneurysm here prone to rupture Enlarged draining vein Encephalomalacia may be present due to “steal” phenomenon CT: vessels appear iso-hyperdense due to blood; calcification may be seen MRI: serpentine flow voids Tx: depends on size, location Embo, Sx, radiation Embo often staged; as AVM is occluded, avoid increased blood flow to ischemic brain which can become edematous and hemorrhage 15% are dural; 50% in PF – dural arterial flow; drains into sigmoid/transverse sinuses; etiology – venous thrombosis and development of collaterals with venous hypertension; if blood drains into cortical veins – at risk for venous infarction and/or intracranial hemorrhage (intraparechymal/SAH) |
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Abnormal signal deep gray
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Degenerative
Metabolic Toxic |
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Bilateral thalamic lesions (high T2)
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Venous or arterial (basilar tip) infarct
Encephalitis Glioma Metabolic – anoxia, Wernike, Wilson, osmotic myelinolysis |
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BG Hi T1
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Hypoxic-ischemic encephalopathy - neonates
liver failure hyperpara & hypopara & pseudohypo hyperalimentation porto systemic shunt depo of paramag ions- low on T2, globus pallidus- Krabbe’s dz |
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BG hi T2, symmetric
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anoxia- CO, smoke inhalation, near drowning
Leigh’s dz- sporadic, lactic acidosis Creutzfeldt-Jakob dz- caudate head and putamen Hallervorden-Spatz dz- destruction of globus pallidus and substantia nigra- initial low T2 of globus pallidus then hi T2 |
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Low T2 globus pallidus and thalami
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never NL (iron depo)- nonspecific- neurodegenerative
Demyelinating (MS) Leukodystrophy- Krabbe’s Brain anoxia/infarct Wilson’s Hallervorden-Spatz Metabolic Sig head trauma |
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BG Calcs
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in utero HIV
hyperpara & hypopara tb, cysticercosis CO- globus pallidus Lead Idio- senecent- g.p. Fahr dz- familial cerebrovascular ferrocalcinosis- extensive bilat bg calc & dentate nuclei & wm- deep & subcortical |
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Leptomeningeal enhancement
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Mets- primary CNS and non- PNET, med, lung, breast, lymphoma, melanoma
Meningitis- bact, TB, fungal, chemical –rupture dermoid Sarcoid- also parenchymal and mimic meningioma SAH, old Post surgical |
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Leptomeningeal carcinomatosis
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mimic meningitis
cranial nerve palsies, hcp (involve basal cisterns) 1° cns adeno (breast, lung) leukemia/lymphoma |
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Dural enhencement
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Mets- prostate, breast, neuroblastoma (kid)
Lymphoma/leukemia Child - neuroblastoma Meningioma Granulomatous- TB, sarcoid, Wegener’s Spont iC hypotension – post LP Post cranial sx Chronic subdural hematoma Idiopathic hypertrophic pachymeningitis |
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Enhancing ventricular margins
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Subependymal mets- lung, breast, melanoma
Sub/ependymal seeding of CNS primary- med, glioma, epen Lymphoma Inflammatory ventriculitis |
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WM abnormality
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MS- Marburg (acute, younger, fever, rapid,extensive), Devic (optic neuritis and cord), tumefactive
ADEM- Hursts (acute hemorrhagic leukoencephalitis), viral, vax. monophasic PML SSPE? Vasculitis Migraine Lyme Leukodystrophy CADASIL- Cerebral Aut Dom Arteriopathy c Subcortical Infarcts & Leukoencephalopathy MVID DAI Diffuse necrotizing leukoencephalopathy- intrathecal MTX, RT Transependymal CSF flow |
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Epidural and subdural abscess/empyema
(head) |
Extension from sinusitis, frontal
Craniotomy Meningitis Epidural- thru midline but not sutures Cx: cerebritis, abscess, venous sinus thrombosis |
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Basal meningitis (granulomatous)
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TB
Sarcoidosis – likes cranial nerves – optic nerve Fungal- crypto, candida, cocci, mucor, blasto, nocardia, actino Cerebritis, abscess, HCP |
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Infections
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HSV- med TEMPORAL, insula, limbic, usu uni, edema, hem, enhance, can be bi
HIV- atrophy, PV wm dz, often c CMV Cysticercosis parenchymal- sz, neuro def intraventricular- obs hcp subarachnoid- comm hcp IM cord-rare Cryptococcosis- gelatinous pseudocysts, meningitis Abscess- thin wall cventral- rupture into vent, ventriculitis (ependymitis) |
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Limbic encephalitis
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Paraneoplastic- small cell (also cerebellar degen), ovarian, GI, breast, Hodgink, NB
Autoimmune. AMS, memory impaired Medial temporal lobes, hypothal, +/- mild enhance, usu bilat Ddx: herpes, CO (c globus pallidus involvement) |
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Rhombencephalitis- LISTERIA
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immunocomp, occupational (farm animals)
meningitis or enceph predilection for BRAINSTEM & CEREBELLUM may enhance can cause abscess ddx: tb, syphilis, sarcoid, ms, adem |
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SSPE (subacute sclerosing panencephalitis)
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P measles, p 5 y
Slow, preogressive or rapid PVWM, BG, cerebellum, brainstem No enhancement, later-diffuse cortical atrophy |
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Holoprosencephaly- no septum pellucidum in all
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Alobar- c severe facial anomalies, monoventricle, fused thal
Semilobar- intermediate- aprtial falx/fissure, partial occipital Lobar- mild- unseparate frontal horns, falx may be present Trisomies 13, 18 |
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Hydranencephaly
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Sec to in utero vascular insult- spared post fossa
alobar holoprosencephaly- no septum/fissure bilat open lip schizencephaly- assoc c septo-optic dysplasia, interhem fissure preserved maximal hydrocephalus- thinned but present mantle of cortex |
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NF
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optic gliomas c extension to tracts
cerebral gliomas UBO- brainstem, pons, BG, thal, cerebellum- can enhance, dysmyel? *think of neurocut stuff in kids- nf, ts, s-w |
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NF2
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bilat vestib schwannoma (or ther CN)
meningioma ependymoma |
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Alexander’s dz
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dysmyelinating. M, sporadic, big head, frontal to post
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Dysmyelinating dz
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Alexander’s- M, sporadic, big head, frontal to post
Canavan’s dz- jewish, AR, big head, occipital, extensive peripheral WM involvement* Krabbe’s dz- dense thalami, corona, caudate body (low T2- paramagnetic) Adrenoleukodystrphy- central occipital to periph and anterior, X Metachromatic leukodystrophy- most common hereditary, AR, symmetric pvwm, atrophy Leigh’s dz (subacute necrotizing ecephalopathy)- AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT) |
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Canavan’s dz
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Dysmyelinating dz. jewish, AR, big head, occipital, extensive peripheral WM involvement*
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Krabbe's dz
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Dysmyelinating dz. dense thalami, corona, caudate body (low T2- paramagnetic)
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Adrenoleukodystrophy
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Dysmyelinating dz. central occipital to periph and anterior,5-10 yrs, x linked
symmetric, confluent posterior white matter, atrophy peripheral rim enhancement- active calcs unusual long chain fatty acids adrenal insufficiency |
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Metachromatic leukodystrophy
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Dysmyelinating dz. most common hereditary, AR, symmetric pvwm, atrophy
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Leigh's dz (subacute necrotizing encephalopathy)
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Dysmyelinating dz. AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT)
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Agnesis of corpus callosum
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assoc c: (colpocephaly, bat wing, high riding V3, absent septum pellucidum)
HCP Dandy-walker Chiari II Midline lipoma- interhem, suprasellar and quad cisterns, not true neoplasm Holoprosencephaly Porencephaly Encephalocele Can be isolated, Probst bundles, absent cingulate gyrus Ant CC usu present c dysgenesis |
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Absence Of Septum Pellucidum
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Holoprosencephaly
Septo-optic dysplasia- assoc c schizencephaly, absent olfactory bulbs Callosal agenesis Schizencephaly Severe chronic hydrocephalus Destructive porencephaly |
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Heterotopia
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Migrational anomaly, sz
Subependymal, ant and post horns- iso to GM, no enhance Band (laminar)- subcortical WM Ddx: subependymal tumor spread, heme, vascular malform, TS, IV meningioma, NF |
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Rhombencephalosynapsis
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fused cerebellum, dent nuclei, sup cerer peduncle, thal
absent vermis, v4 pointed post- keyhole absent septum pellucidum |
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Gray matter heterotopia
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Subependymal
Deep white matter Band heterotopia- often symmetric |
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Sturge-Weber
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facial vascular nevus in the territory of the ophthalmic division of the trigeminal nerve, seizures, dementia, hemiplegia, hemianopsia, and congenital glaucoma or buphthalmos
sporadic characteristic leptomeningeal venous angioma (subarachnoid space) and facial nevus are most commonly unilateral, but may be bilateral Intraparenchymal calcification, parenchymal volume loss, engorgement of deep veins, and leptomeningeal and choroid plexus angiomata*- calcify and hi T2 Cortical calcs: pericapillary distribution in the fourth layer of the atrophied cerebral cortex- may not see on MR- gre/T2 only Mr: thickened ctx and dec convolutions- Atrophy Assoc c ddm synd |
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Dyke davidoff mason
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Ipsilateral hypertrophy of cranium secondary to cerebral hemiatrophy (compensatory thickening of inner table)
Enlarged orbits, sinuses, mastoids, thick ctx Sec to vasc insult Also c Sturge-Weber |
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J-shaped sella
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CONMAN
Chronic hydrocephalus Optic glioma, OI neurofibromatosis Mucopolysaccharidosis Achonondroplasia Normal variant |
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Basilar invagination
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Chamberlain and McGregor’s line- dens>5 mm above- superior migration of dens thru foramen magnum
Compresses cord/brainstem "PF ROACH" Paget disease Fibrous dysplasia Rickets Osteogenesis imperfecta, Osteomalacia Achondroplasia Cleidocranial dysplasia Hyperparathyroidism, Hurler syndrome |
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Wernike’s encephalopathy
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Bilat symmetric thalamic hi T2
Alcoholics and vomiting preg Reversible c thiamine Ddx: osmotic myelinolysis |
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Cerebellar atrophy
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Generalized- c cerebral atrophy
Olivopontocerebellar degeneration- Friedreich ataxia Ataxia-telangiectasia – AR, sinopulm infections, ICH, lymphoma/leukemia EtOH- midline (vermis) Dilantin Paraneoplastic (usu small cell) Radiation Focal- trauma, infarct |
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Posterior reversible encephalopathy syndrome (PRES)
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@ g-w jxn, ext capsule, bg, cortical & subcortical wm (OCCIPITAL)- neg DWI
sz, visual disturbance, obtundation, resolves w/in days HTN-acute elev of BP as little as 10 mmHg preeclampsia/eclampsia - htn, proteinuria, +sz/coma Cyclosporine toxicity, OKT3- immunosup Cocaine, heroin Chemorx: MTX, cisplatin CRF? TTP, HUS? SLE(rare) |
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Diffuse cerebral atrophy
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Degenerative - Alzheimer’s, Pick, J-C dz- caudate head/putamen and cortical gyriform hi T2, no WM/gad
MS, encephalitis Trauma Radiation Drugs- dilantin, steroids, MTX, pot, chemo, EtOH HIV encephalopathy Infarcts Renal failure Age Anorexia Dyke-davidoff-mason- unilat |
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Gyral enhacement
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Meningeal carcinomatosis- breast, lung, melanoma, lymphoma
Primary cns tumor c seeding- medulloblastoma, pineoblastoma, ependymoma Meningitis- any Cerebritis- focal/encephalitis- diffuse, viral SAH Subacute infarct |
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Ventricular margin enhancement
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Subependymal met extension- small cell, breast, melanoma
Subependymal seeding of CNS primary- glioma, ependymoma, medulloblastoma, germinoma Lymphoma Ventriculitis- rupture or from basal cisterns |
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Ventriculitis
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Trauma
Absecess rupture Bacteremia Surgical (shunt) Meningitis Hiv- CMV, lymphoma |
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Diffuse axonal injury (DAI)
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Locations
1. Lobar WM- F/T 2. CC- posterior 3. Brain stem- dorsolateral pons/mid Shearing, petch hem later Severe neuro deficit |
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Persistent trigeminal artery
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up to 1/2%
hypoglossal & otic assoc c avm & aneurysms can course thru sella** usu precavernous, can be intracavernous prox basilar & distal vert & pcom can be hypoplastic assoc c tic doloureux & vb insuff |
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Spontaneous intracranial hypotension
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Postural HA
Iatrogenic (LP, surgery), spontaneous (rupture of Tarlov cyst), trauma, thoracic diverticula Chronic, intermittent CSF leak Low-lying tonsils, elongated V4, bilat dubdural effusion, dural enhancement |
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CNS vasculitis
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infect- tb, syphilis
non-infect Primary angiitis PAN Sarcoid wegener's coll-vasc- SLE, RA antiphospholipid ab- ischemia drugs- amph, x, coke primary (isolated) angiitis of the CNS (PACNS) no systemic vasculitis *systemic c CNS involvement Churg-Strauss PAN** (most cmmn to affect CNS) Microscopic polyangiitis (lung and kids) Wegener's Behcet's dz- nonspec, BG, brainstem, WM giant cell arteritis SLE usu stroke antiphospholipid ra, scleroderma, sjogren's |
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Lhermitte-duclos
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posterior fossa dysplasia, mimicking a space-occupying lesion; aka - dysplastic gangliocytoma of the cerebellum and is considered a complex hamartoma; may occupy an entire cerebellar hemisphere; macroscopically the cerebellar folia appear hyperplastic. CT may be misleading since it shows a poorly delineated iso- or hypointense posterior fossa lesion without enhancement but with deformity of the fourth ventricle associated sometimes to hydrocephalus, that may mimic a posterior fossa neoplasm. MR shows a characteristic T2 pattern of laminated increased signal – like “tiger stripes”
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MELAS
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(mitochondrial encephalopathy, lactic acidosis and stroke)- infarcts not confined by vascular territory, spares WM, hits cortex where there is high metabolic activity, familial
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MERRF
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myoclonus, epilepsy, ragged red fibers)- adults
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